Safelist Constant Contact web domains in a security program

Prevent integration and email display issues by adding Constant Contact URLs or IP addresses to a security program's safelist

Important: Some security programs prompt you to restart your computer to allow the changes to take effect.

If you're experiencing issues with certain integrations, or if your contacts are telling you they're receiving your email but the content isn't displaying properly, a good place to start is to have them check the settings in their email client and their web browser to ensure images are enabled.

If those actions don't help, the next step is to check their security program, which is any filtering system they have in place to protect malicious content from reaching them, like Office 365 or Microsoft Defender, or it can be their mailbox setup. Firewall and intrusion prevention security programs can block URLs or IP addresses, which can prevent images from showing in your emails or the web version of your email from displaying. Your contacts may need to talk to their mail admin or IT person to discuss what's causing the URLs to be blocked.

Your contact can tell a security program that content from Constant Contact is okay to view by putting Constant Contact's domains or IP addresses on a safelist (formerly referred to as a whitelist):

• Constant Contact URLs
• Constant Contact IP addresses to safelist to fix email issues
• Constant Contact IP addresses to safelist to fix integration issues

Constant Contact URLs

If the program allows website URLs, have your contact copy the following Constant Contact URLs and add them to their safelist:

• constantcontact.com
• conta.cc
• http://static.ctctcdn.com
• lp.constantcontactpages.com
• files.ctctcdn.com
• files.constantcontact.com
• files.ctctusercontent.com
• b.ctct.sh
• a.rs6.net
• rs6.net
• s3.amazon.com

Did you know? The URLs you added as text links, button links, or clickable image links in your email can also cause your email to be blocked by a security program. If you've added all the URLs in the above list to a safelist and are still being blocked, a good next step is to check your own content for anything that may have triggered your email to be blocked.

Constant Contact IP addresses to safelist to fix email issues

If the program allows IP addresses, have your contact add these Constant Contact IP Ranges to their safelist:

• 208.75.123.0/24
• 205.207.106.0/24

The formatting (CIDR notation) above signifies a range of IP addresses which is equivalent to 208.75.123.* and 205.207.106.*

Constant Contact IP addresses to safelist to fix integration issues

Safelist these Constant Contact IP addresses for integration functionality:

208.75.122.0/23
205.207.106.0/24
54.210.128.217
18.209.130.239
18.204.73.133
35.170.27.118
44.218.126.76
34.195.196.167
44.212.165.8
44.223.163.70

Questions?